This may be put on legal documents, we hear (4)
I believe the answer is:
ritz
'this may be put on' is the definition.
'legal documents we hear' is the wordplay.
'legal documents' becomes 'writs' (writ is a kind of legal document).
'we hear' indicates a 'sounds like' (homophone) clue.
'writs' sounds like 'RITZ'.
(Other definitions for ritz that I've seen before include "Elegant hotel" , "Grand hotel" , "Place of expensive luxury" , "Luxury hotel" , "Cesar --, Swiss hotelier" .)